Heme synthesis in yeast does not require oxygen as an obligatory electron acceptor.

In a previous paper (Krawiec, Z., Biliński, T., Schüller, C. & Ruis, H., 2000, Acta Biochim. Polon. 47, 201-207) we have shown that catalase T holoenzyme is synthesized in the absence of oxygen after treatment of anaerobic yeast cultures with 0.3 M. NaCl, or during heat shock. This finding suggests that heme moiety of the enzyme can either be formed de novo in the absence of oxygen, or derives from the preexisting heme pool present in cells used as inoculum. The strain bearing hem1 mutation, resulting in inability to form δ-aminolevulinate (ALA), the first committed precursor of heme, was used in order to form heme-depleted cells used as inocula. The cultures were supplemented with ALA at the end of anaerobic growth prior the stress treatment. The appearance of active catalase T in the stressed cells strongly suggests that heme moiety of catalase T is formed in the absence of oxygen. This finding suggests the necessity to reconsider current opinions concerning mechanisms of heme synthesis and the role of heme as an oxygen sensor

Chemical Composition, Antioxidant and Antimicrobial Activity of Raspberry, Blackberry and Raspberry-Blackberry Hybrid Leaf Buds

In our investigation, the chemical composition and bioactive potential of leaf buds of raspberry, blackberry, and a raspberry-blackberry hybrid were determined. Antioxidant and antimicrobial properties were tested in water (W), ethanol-water (EW), and glycerol-water (GW) extracts from the buds. These plant organs contain relatively large amounts of minerals, especially Fe. The total antioxidant capacity (TAC) measured by the ABTS and DPPH methods ranged from 2.86 to 12.19 and 6.75 to 24.26 mmol per 100 g fresh weight (FW) of buds, respectively. TAC values were generally higher in the raspberry than in the case of blackberry and raspberry-blackberry hybrid extracts. The antioxidant properties of the extracts were strongly positively correlated with their content of total phenolic (TP). No such relationship was noted for ascorbic acid (AA), whose concentration in all extracts was at a similarly low level. Antioxidant properties determined in vitro were confirmed for the GW extract from raspberry leaf buds in biological test based on the growth parameters of Δsod1 Saccharomyces cerevisiae mutant cells in hypertonic medium. The extracts also exhibited strong antibacterial properties against Staphylococcus aureus and Enterococcus faecalis and weaker against Enterobacter aerogenes. The studied leaf buds could be therefore an unconventional source of minerals, natural antioxidants and antibacterial compounds with potential applications in the food, pharmaceutical, and cosmetics industries

Chemical Composition, Antioxidant and Antimicrobial Activity of Raspberry, Blackberry and Raspberry-Blackberry Hybrid Leaf Buds

In our investigation, the chemical composition and bioactive potential of leaf buds of raspberry, blackberry, and a raspberry-blackberry hybrid were determined. Antioxidant and antimicrobial properties were tested in water (W), ethanol-water (EW), and glycerol-water (GW) extracts from the buds. These plant organs contain relatively large amounts of minerals, especially Fe. The total antioxidant capacity (TAC) measured by the ABTS and DPPH methods ranged from 2.86 to 12.19 and 6.75 to 24.26 mmol per 100 g fresh weight (FW) of buds, respectively. TAC values were generally higher in the raspberry than in the case of blackberry and raspberry-blackberry hybrid extracts. The antioxidant properties of the extracts were strongly positively correlated with their content of total phenolic (TP). No such relationship was noted for ascorbic acid (AA), whose concentration in all extracts was at a similarly low level. Antioxidant properties determined in vitro were confirmed for the GW extract from raspberry leaf buds in biological test based on the growth parameters of Δsod1 Saccharomyces cerevisiae mutant cells in hypertonic medium. The extracts also exhibited strong antibacterial properties against Staphylococcus aureus and Enterococcus faecalis and weaker against Enterobacter aerogenes. The studied leaf buds could be therefore an unconventional source of minerals, natural antioxidants and antibacterial compounds with potential applications in the food, pharmaceutical, and cosmetics industries

Ocena toksyczności azoksystrobiny dla saprofitycznych grzybów oraz rzodkiewki we wczesnych stadiach wzrostu

The aim of the study was to assess the toxicity of azoxystrobin, a fungicide belonging to the strobilurin class, for selected saprophytic fungi (Saccharomyces cerevisiae and Penicillium sp.) and for radish (Raphanus sativus L.) The parameters of fungi growth and the early development stages of radish were analysed. Based on the sensitivity of the organisms and their physiological processes to azoxystrobin, they can be arranged in the following order: growth of sod1 S. cerevisiae mutant, growth of wild-type S. cerevisiae, growth of Penicillium sp., respiration of germinating radish seeds, early seed germination, elongation of roots and seedlings, late seed germination. The mechanism of azoxystrobin toxicity seems to be associated with cellular antioxidant status.Celem badań była ocena toksyczności azoksytrobiny, fungicydu należącego do klasy strobiluryn dla saprofitycznych grzybów (Saccharomyces cerevisiae i Penicillium sp.) oraz rzodkiewki (Raphanus sativus L.). Analizowano wzrost drożdży szczepu dzikiego i jego mutanta bezdysmutazowego sod1, grzyba strzępkowego Penicillium sp. oraz parametry biochemiczne i fizjologiczne kiełkujących nasion rzodkiewki i powstałych z nich siewek. Najbardziej wrażliwym na azoksytrobinę okazał się wzrost drożdży (mutanta sod1, następnie szczepu dzikiego wt) w następnej kolejności: wzrost grzybni Penicillium, oddychanie kiełkujących nasion rzodkiewki, proces kiełkowania oznaczany po 24 godzinach od wysiewu nasion, wydłużanie korzeni, wydłużanie siewek, proces kiełkowania określany po 96 godzinach. Mechanizm toksyczności azoksytrobiny wydaje się być powiązany z aktywnością komórkowego systemu antyoksydacynego

The Antioxidant Properties and Biological Quality of Radish Seedlings Biofortified with Iodine

Iodine is an essential trace element for humans, and iodine deficiency is a significant health problem. In this study, an improved method for iodine biofortification based on seed germination was established. Solutions of KI (0.15, 0.30, 0.75 and 1.5 mg∙g−1 of seeds) were applied to germinating radish seeds of two cultivars Raphanus sativus L. var. sativus: Warta and Zlata. Compared with the control (seeds treated with water) the iodine content (in the radish sprouts produced by germinating seeds treated with KI were approximately 112.9–2730 times higher. The application KI rates did not adversely affect the biological quality of the radish sprouts. Regarding the biological quality of the iodine-enriched seedlings, we determined their length, dry mater, protein, soluble sugars, chlorophylls, total phenol, ascorbic acid, thiol group content and total antioxidant capacity. The effect of potassium iodide on the selected parameters of their biological quality varied depending on the KI doses and radish cultivars. The results showed that the most appropriate biofortification application rates were 0.15 and 0.30 mg KI per g seeds, because the enriched seedlings had excellent biological quality parameters

Zawartość azotanów w liściach roślin warzywnych i zielarskich z ogrodów gospodarstw agroturystycznych

The objective of the research study was to compare of the nitrate content in leafy vegetables (lettuce, spinach) and herbal plants (basil, peppermint, oregano and thyme) from the home gardens of agrotourist farms located in the Central Roztocze region. The obtained results have shown that the content of nitrates in the studied plants depended on the plant species, physiological phase of plant development and the method of plant cultivation. The content of nitrates in the leaves of studied plant species was the following: lettuce > spinach > basil > peppermint > oregano >> thyme. Plants cultivated by conventional method accumulated the largest amounts of nitrates; when integrated method was used, less nitrates were accumulated and when organic method was used, the content of accumulated nitrates was the smallest. At the early stage of vegetative development the plants contained twice as much nitrates as the plants at the ripe vegetative stage. At the juvenile vegetative stage the content of nitrates exceeded the legally permissible content in lettuce, spinach and basil from conventional and integrated gardens. At the ripe vegetative stage the content of nitrates in all the studied plant species did not exceed the legally permissible content of these compounds in leafy vegetables with a short vegetative term.Celem przeprowadzonych badań było porównanie zawartości azotanów w liściach roślin warzywnych (sałata, szpinak) i zielarskich (bazylia, mięta pieprzowa, lebiodka pospolita zwana również oregano, tymianek) uprawianych w ogrodach przydomowych gospodarstw agroturystycznych, zlokalizowanych na Roztoczu Środkowym. Uzyskane wyniki wykazały, że poziom fitoakumulacji azotanów zależał od gatunku i fizjologicznej fazy rozwoju rośliny oraz metody uprawy. Zawartość azotanów w liściach badanych gatunkach roślin kształtowała się następująco: sałata > szpinak > bazylia > mięta pieprzowa > lebiodka pospolita, zwana oregano >> tymianek. Najwięcej azotanów gromadziły rośliny uprawiane metodą konwencjonalną, mniej metodą integrowaną, a najmniej metodą organiczną. Rośliny we wczesnej fazie wegetatywnej zawierały około dwukrotnie więcej azotanów niż rośliny w dojrzałej fazie wegetatywnej. W juwenilnej fazie wegetatywnej zawartości azotanów przekraczały prawnie dopuszczalne ich zawartości w sałacie, szpinaku i bazylii z ogrodów konwencjonalnych i integrowanych. W dojrzałej fazie wegetatywnej zawartości azotanów we wszystkich badanych gatunkach roślin nie przekroczyły prawnie dopuszczalnych zawartości tych związków w warzywach liściowych o krótkim okresie wegetacji

Effect of stress on the life span of the yeast Saccharomyces cerevisiae.

A correlation is known to exist in yeast and other organisms between the cellular resistance to stress and the life span. The aim of this study was to examine whether stress treatment does affect the generative life span of yeast cells. Both heat shock (38°C, 30 min) and osmotic stress (0.3 M NaCl, 1 h) applied cyclically were found to increase the mean and maximum life span of Saccharomyces cerevisiae. Both effects were more pronounced in superoxide dismutase-deficient yeast strains (up to 50% prolongation of mean life span and up to 30% prolongation of maximum life span) than in their wild-type counterparts. These data point to the importance of the antioxidant barrier in the stress-induced prolongation of yeast life span

Jakość biologiczna zielonych roślin pszenżyta biofortyfikowanych jodem

Plant biofortified with iodine may be an alternative source of this element in human diet. The purpose of the research was to determine the effect of fertilization on quality of green plant biological iodine. Iodine in the form of KIO3 or KI was applied to the soil or sprayed on the plants. Iodine application (2.50 or 5 kg ∙ ha–1) was split, with the first half applied together with spring nitrogen fertilization and the other half applied one month before sampling for laboratory tests. In all the tested combinations of fertilization iodine increases iodine content in green plants compared to control. The application rates and means of fertilization with iodine salts did not adversely affect the biological quality of the plants.Rośliny biofortyfikowane jodem mogą być alternatywnym źródłem tego pierwiastka w diecie człowieka. Celem badań było określenie wpływu nawożenia jodem na jakość biologiczną zielonych roślin pszenżyta. Jod w postaci KIO3 lub KI (2,50 lub 5 kg ∙ ha–1) był stosowany w glebie lub rozpylany na rośliny. Dawka jodu została podzielona, pierwszą połowę stosowano wraz z wiosennym nawożeniem azotem, a drugą połowę stosowano na jeden miesiąc przed pobraniem próbek do badań laboratoryjnych. We wszystkich badanych kombinacjach nawożenia jodem obserwowano wzrost zawartości jodu w zielonych roślinach pszenżyta w porównaniu do kontroli. Zastosowane dawki i sposoby nawożenia solami jodu nie wpłynęły negatywnie na jakość biologiczną zielonych roślin pszenżyta